96 LX Civic. I already have sport shocks, springs, rear sway bar (22mm) camber kit F/R and Rota Slip 15x7 with Kumhos. This is my daily driver. Would adding a rear strut bar make any noticeable difference?

NO, but it won't hurt. Upper bars do a little work, but not as much as you would think. Get a solid type bar or one with 2 bolts per side(neuspeed). Otherwise your stuck with a "hinged" bar one bolt per side, this bar does NOTHING!

NO, but it won't hurt. Upper bars do a little work, but not as much as you would think. Get a solid type bar or one with 2 bolts per side(neuspeed). Otherwise your stuck with a "hinged" bar one bolt per side, this bar does NOTHING!

Yup, with double wishbone type suspensions the shock tower really doesnt see that much lateral stress (what a tie bar would reduce).... However on the newer civics, with struts. a tie bar can help improve chassis responsiveness, but even then its of limited use, given that the shock towers are so close to the fire wall.